Apparatus for recording and reproducing sound on elongated recording mediums



Nov; 22, 1960 F. HOLMBERG 2,961,180

APPARATUS FoR RECORDING AND REPRODUCING SOUND ON ELONGATED RECORDING MEDIUMS Filed Dec. 5, 1956 IN VEN TOR.

United States Patent O i APPARATUS FOR RECRDENG AND REPRODUC- ING SOUND N ELDNGATED RECORDING MEDIUMS Folke Holmberg, Motala, Sweden, assignor to Industriaktiebolaget Luxor, Motaia, Sweden, a corporation of Sweden Filed Dec. 3, 1956, Ser. No. 625,822

Claims priority, application Sweden Dec. 8, 1955 4 Claims. (Cl. 242-5512) The present invention relates to an improvement in apparatus for recording and reproducing sound on elongated recording mediums, which are wound from one spool to another, the recording medium being provided with a specially formed end portion for effecting an impulse to an actuating device, which thereby brings a startstop device to its stop position for stopping the apparatus or actuates a reverse device for reversing the direction of the medium travel.

It is known from magnetic recording and reproducing apparatus to have a recording tape consisting of an electrically non-conductive paper or plastic base provided with a magnetizable coating, and to add to its ends a special ribbon consisting of or coated with a metallic, electrically conductive material, which ribbon, when it passes two contacts insulated from each other and arranged in the apparatus, connects these contacts and thereby effects an impulse to a stop device, which stops the apparatus.

This stop device usually consists of a catch for the start knob, which catch is withdrawn from its locking position by the actuating device when this device gets an impulse from the end ribbon, so that the start knob is automatically moved to its neutral position, thereby switching off the current to the motor of the apparatus.

In order to start the apparatus once again the spools have to be turned by hand, so that the end ribbon of the tape no longer connects the two contacts. Otherwise the start knob will be held in its start position for a time, which causes continued impulses to the actuating device and repeated movements of the catch to and from the locking position, this procedure going on until the end ribbon has passed the contacts.

The present invention has for its object to avoid these disadvantages.

The device according to the invention will be described in the following with reference to the accomapnying drawing, in which:

Figure l -is a schematic view of the device according to one embodiment of the present invention,

Figure 2 is a schematic view of the same device in another working position, and

Figure 3 shows the conductive end portions of a recording tape.

In the drawing, 1 designates a relay coil belonging to a relay which, in a manner known before, regulates a catch 18 of a start knob 19 in a magnetic recording and reproducing apparatus so that, when lthe current ows through the coil and the relay attracts, the catch 1S is brought to a position locking the start knob 19 of the apparatus in an inner position while, when the current through the coil l ceases, the catch 18 yis by means of a spring 28 withdrawn from its locking position and the knob 19 is then by a pressure spring 21 moved to an outer position to stop the tape by actuation of the tape direction-reversing device 22 in a well-known manner.

The one end of the coil is connected to positive potential as shown in the drawing while its other end is Patented Nov. 22, 1960 connected to a point having ground potential. Two stationary contacts 2 and 3 have also ground potential. The rst one of these contacts is constituted by a pin 2, which is in the path of travel of a magnetic tape 4. In the path of travel of this tape there is also a second pin 5, which is electrically insulated from the pin 2. The pin 5 is arranged on an arm 6, which is rotatably pivoted about a shaft 7 and by means of a spring S tends to tu-rn in counterclockwise direction about this shaft, but is prevented therefrom as long as the tape 4 travels between its two spools (not shown) in normal manner. The end of the arm 6 opposite to the pin 5 cooperates with a resilient strip 9, which normally is held -in the position shown in the figures, but is pressed downwards by the arm 6 into contact with the stationary contact 3 mentioned before when this arm by means of the spring 8 is given an opportunity to rotate about the shaft 7 in counterclockwise direction. The strip 9 is connected to the positive end of the coil 1. To this end there is also connected a further stationary contact lil, which cooperates with a movable contact arm 11. The latter is rotatable about a shaft 12 and tends to turn in counterclock-wise direction into contact with the contact 10 by means of a spring 13. On the contact arm 11 there is rotatably arranged a screw follower 14, which cooperates with the thread of a screw 15, which in dependence of the rotation of the spools alternately rotates in two opposite directions. The screw follower 14 is resiliently held in the position shown in Fig. l in relation -to the contact arm 11V but can be turned about its bear-ing in this arm in both directions. The stationary Contact 10 and the shaft 12 are arranged on a plate (not shown), which is displaceable in the directions indicated by the arrow 16. When the apparatus is started through actuation of its start knob 19 this plate is temporarily displaced downwards in the plane of the drawing thereby disengaging the screw follower 14 from the screw 15. After that the plate immediately returns to Iits initial position with the screw follower 14 in engagement with the screw 15.

The contact arm 11 is connected to the arm 6 through a lead 17 whereby the pin 5 is electrically connected to Vthe contact arm 11.

During the normal operation of the apparatus the details are in the positions shown in Fig. 2 with the coutacts 5 and 2 and also 9 and 3 open and the contacts 10 and 11 closed. As also seen from this figure the electrically non-conductive tape 4 is pass-ing the contact pins 5 and 2.

lf a break in the tape occurs this means that the spring 8 will-be free to turn the arm 6 in counterclockwise direction. This arm thereby presses the strip 9 against the stationary contact 3. Thus the coil 1 is short-circuited, which causes the start knob 15* of the apparatus to be released and the apparatus is stopped.

On the other hand if the tape travels from the one spool to the other without any breakage the electrically conductive end ribbon 23 of the tape, as shown in Figure 3, will pass the two pins 5 and 2 when the tape is almost entirely unwound from the supply spool. This means that the coil '1 .of the relay is short-circuited through the contacts 10 and 11, the lead 17, the arm V6, the pin 5, the conductive end ribbon 2-3 of the tape and the pin 2, whereby the apparatus is stopped before the tape 4 has been totally unwound from the supply spool.

If it is now desired to rewind the tape the start knob 19 is set in a corresponding manner and at the same time the apparatus is started. Thereby the plate mentioned before together with the contact group 19, 11 is displaced downwards in the plane of the drawing and is immediately returned to `its initial position. This means that the screw follower 14 during the final part of the return movement of the plate is engaged with the screw 15, so that the contact arm 11 is forced to rotate in clockwise direction. The details now occupy the positions shown in Fig. 1. According to this figure the contacts 10 and'11 are disconnected and thus the conductive end ribbon 23 engaging the pins and 2 is caused to be out of function.

It is therefore possible to ltransport the tape without any act-ion on the relay. During this transport the screw 15 rotates in the one or other direction thereby bringing the screw follower 14 to the right or left. When a predetermined Ilength of the tape has been transported to the take-up spool the screw follower 14 has reached the right or left end of the screw 15 and will drop outside its edge. (See Fig. 2, where the right end position of the screw follower 14 is shown in full lines and its left end posi- Vtion in dotted lines.) In these end positions of the screw follower there is nothing preventing the spring 13 to rotate the contact arm 11 in counterclockwise direction and bring it -into contact with the contact 10. The device is therefore again prepared for renewed action from the end ribbon of the tape.

On the other hand if it is desired for instance for the purpose of shifting spools to unwind the tape totally from the supply spool after the stopping of the apparatus, the start knob 19 of the latter is set for :resumption of the tape transport just broken. This setting of the start knob 19 also means that the contact Vgro-up 10, 11 is separated in the same manner as is described above when the screw follower 14 engages the screw 15. If the screw follower 14 has not reached the end of the screw 15 when the tape is totally nnwound from the supply spool the desired stopping of the apparatus will, in spite of that, occur as the arm o is no longer pressed down by the tape but is free to rotate in counter clockwise direction, thereby bringing the strip 9V into engagement with the contact 3i, thus short-circuit'ing the coil 1.

It is of course possible to use the described device in an apparatus where it is desired to use the conductive end ribbon of the tape for obtaining an automatic reverse of the tape. The device is then to be so arranged that instead of a stopping device, a reversing device 22 is actuated by the relay in a well-known manner at the same time the delay device, consisting of the screw 15 and the screw follower 14, is started.

What I claim is:

1. In an apparatus for recording and reproducing sound on an elongated recording medium which travels from one spool to another, said medium comprising a non-conducting base and being provided with end portions of a conducting material, means for moving said medium from one spool to another, a vstart-stop device for said apparatus, a relay for holding said start-stop device, when de-energized, in its stop position and, when energized, in its start position, a source of current for said relay, a iirst pair of electric contacts in parallel with said relay placed in the travelling path of the recording medium to be closed by said conducting end portion of said recording medium, a second pair of electric contacts in series wi-th said first pair of electric contacts, the closing and opening of said second pair of electric con tacts being controlled by a delay mechanism having a time-limited'running period, said delay mechanism being operatively connected to the recording medium to be driven from said medium when this is travelling from one spool toranother.

2. In an apparatus for recording and reproducing sound on an elongated recording medium which travels from one spool to another, said medium comprising a nonconducting base and being provided with end portions of a conducting material, means for moving said medium from one spool to another, a reverse device for said apparatus to change automatically the travel direction of said medium, a relay for eiectuating, when de-energized, said reverse device to cause said change, a source of current for said relay, a first pair of electric contacts in parallel with said relay placed in the travelling path of the recording medium to be closed by said conducting end portion of said recording medium, a second pair of electric contacts in series with said first pair of electric contacts, the closing and opening of said second pair of electric contacts being controlled by a delay mechanism having a time-limited :running period, said delay mechanism being operatively connected to the recording medium to be driven from said medium when this is travelling from one spool to another. Y

3. In an apparatus for recording and reproducing sound on an elongated recording medium which travels from one spool to another, said medium compris-ing a nonconducting base and being provided with end portions of a conducting material, means for moving said medium from one spool to another, a start-stop device for said apparatus, a relay for holding said start-stop device, when energized, in its stop position and, when de-energized, in its start position, a source of current for said relay, a iirst pair of electric contacts in series with said relay placed in the travelling path of the recording medium to be closed by said conducting end portion of said recording medium, a second pair of electric contacts in series with said rst pair of electric contacts being controlled by a delay mechanism, said delay mechanism having a timelimited running period and being operatively connected to Ithe recording medium to be driven from said medium when this is travelling from one spool to another.

4. In an apparatus for recording and reproducing sound on an elongated recording medium which travels from one spool to another, said medium comprising a nonconducting base and being provided with end portions of a conducting material, means for moving said medium from one spool to another, a reverse device for said apparatus to change automatically the travel direction of said medium, a relay for eiectuating, when energized, said lreverse device to cause said change, a source of current for said relay, a rst pair of electric contacts in series with said relay placed in the travelling path of the recording medium to be closed by said conducting end portion o f said recording medium, a second pair of electric contacts in series with said iirst pair of electric contacts being controlled by a delay mechanism, said delay mechanism having a time-limited running period and being operatively connected to the recording medium to be driven from said medium when this is travelling from one spool to another.

Herzig Dec. 15, 1942 Lindsay n n `luly 13, 1954 

